The invention relates to a network system for laser processing, in particular for industrial production installations, comprising at least a first and a second laser device, each of which has a laser radiation source, at least one output for the laser radiation, a shutter switch disposed between the respective output and the laser radiation source and a laser controller, and also comprising at least one workstation with at least one laser processing head.
Network systems of this type are known from the prior art. However, with these there is the problem of ensuring that the laser radiation from the laser radiation source is only sent to the workstation when the latter has been made safe.
In the case of the known network systems of this type, it is occasionally necessary to change the laser radiation supply to the laser processing head, that is to say the laser processing head initially receives laser radiation from one laser device, but in the case of maintenance work on this laser device or a technical problem on this laser device it is necessary to change to the other laser device, the change from one laser device to the other being carried out manually, since it does not occur very often.
However, this manual change from one laser device to the other entails considerable safety risks.
It is therefore an object of the invention to form a network system of the type described at the beginning in such a way that it can be operated safely.
According to the invention, this object is achieved in the case of a network system of the type described at the beginning by a first light guide, which is led from the output of the first laser device to an optical connection element associated with the workstation, being provided, by a first communication connection element, which is connected to the laser controller of the first laser device via a first communication line, being locally associated with the first optical connection element, by a second light guide, which is led from the output of the second laser device to a second optical connection element associated with the workstation, being provided, which a second communication connection element, which is connected to the laser controller of the second laser device via a second communication line, is locally fed to the second optical connection element, by the laser processing head being capable of being connected to the first or second optical connection element by means of a mating optical connection part, by a safety circuit, which is capable of being connected to the first or second communication connection element via a mating communication connection part, being associated with the workstation, by a mechanical blocking device, which allows only the mating optical connection part and the mating communication connection part to be connected to the first or second optical connection element and the respectively associated first or second communication connection element, being provided and by each laser controller blocking a closing of the shutter switch of the corresponding laser device if the safety circuit is not connected to the respective communication connection element, and releasing the shutter switch only if the safety circuit of the workstation is connected to the communication connection element connected to the respective laser controller and is not itself emitting a stop signal.
A closing of the shutter switch is understood for the purposes of this invention as meaning that a light path from the laser radiation source to the corresponding output is allowed, so that the laser radiation is passed to the output, while an opening of the shutter switch means that the light path is interrupted, that is to say the laser radiation does not reach the output.
It is consequently to be regarded as the advantage of the solution according to the invention that, in spite of the fact that two optical connection elements of two different laser devices are associated with the workstation, it is not possible to connect the mating optical connection part of the laser processing head to the optical connection element of the one laser device while the mating communication connection part is connected to the communication connection element of the other laser, so that the other laser, to the optical connection element of which the mating optical connection part is not connected, monitors the safety functions of the workstation, in particular the safety circuit of the same, and consequently this laser controller releases its shutter switch as long as the safety circuit does not emit a stop signal, so that, in principle, it could be possible for this laser device to send laser radiation to the optical connection element although the mating connection part is not connected to it.
The converse case is also avoided, that is that the laser device sends laser radiation to that workstation to the optical connection element of which the mating optical connection part is connected but without the laser controller monitoring the safety functions.
In principle, the blocking device may be formed in a wide variety of ways.
For example, the blocking device may be effective between the communication connection element and the optical connection element and be formed for example in such a way that the mating communication connection part can only be connected to the communication connection element if the mating optical connection part is already connected to the associated optical connection element, or vice versa.
However, a solution which is particularly simple mechanically provides that the blocking device is formed as a mechanical connecting element of a specific length between the mating optical connection part and the mating communication connection part and that the first optical connection element and the second communication connection element and also the second optical connection element and the first communication connection element are at a distance from one another which is greater than the length of the connecting element.
Consequently, the connecting element ensures that, whenever for example the mating optical connection part has been brought into connection with the first or second optical connection element, the mating communication connection part can only be brought into connection with the associated communication connection element, since the other communication connection element is so far away that the connecting element no longer allows it to be inserted.
No details have previously been specified regarding the form of the safety circuit. The safety circuit is preferably formed in such a way that it always emits a stop signal when a working area safety device of the workstation is activated.
Such activation of a working area safety device only takes place if, for example, an access to the workstation is open.
A particularly advantageous variant of the solution according to the invention provides that a processing controller is associated with the workstation, that the processing controller is connected to the mating communication connection part and receives information for the identification of the laser device via the communication connection element connected to the mating communication connection part.
This solution has the great advantage that the connection of the mating communication connection part to the corresponding communication connection element simultaneously enables the processing controller to detect which laser device is supplying the laser radiation arriving at the optical connection element and consequently enables it to select and activate the corresponding laser device.
This solution consequently makes it possible to eliminate the possibility of the processing controller actuating a laser device which is not at all capable of supplying laser radiation for the communication connection element connected to the mating communication connection part on account of erroneous existing information or erroneously entered information.
It is even more advantageous if the processing controller receives information for the identification of the output of the laser device and consequently concerning the light path via the communication connection element.
A further advantageous exemplary embodiment of the solution according to the invention provides that the processing controller communicates directly with the respective laser controller, via the mating communication connection part connected to the respective communication element and via the communication line, in order to control the laser device for the processing.
This solution makes considerably faster interaction possible, on account of the direct communication between the processing controller and the laser controller, and consequently saves unnecessary control times.
In addition, this solution inevitably ensures that the processing controller only addresses the laser controller that is capable of supplying laser radiation for the laser processing head controlled by the processing controller.
Consequently, erroneous activations of other laser devices, particularly including those caused by programming errors or direct input errors, are prevented.
As an alternative or addition to the embodiments described above, a particularly advantageous exemplary embodiment of a network system according to the invention provides that a light path monitoring system is associated with the workstation and makes it possible to detect whether there is a continuous light path present between the respective shutter switch and the laser processing head.
A direct light path monitoring system of this type has the advantage of avoiding the situation which may still occur with the exemplary embodiments described above, that is that, although the mating communication connection part is connected to the communication connection element, the mating optical connection part is not connected to the optical connection element, or the connection between the mating optical connection part and the optical connection element has not been properly made, so that the laser radiation is not coupled into the laser processing head, or only to an inadequate degree.
Errors of this type can be directly detected when using a light path monitoring system according to the invention.
A light path monitoring system of this type is preferably formed in such a way that it makes it possible to detect whether the mating optical connection part is correctly connected to one of the optical connection elements.
A detection of this type can be inquired for example by means of limit switches which are operated by mechanical elements and detect whether the mating optical connection part and the optical connection element are connected to each other in the way intended.
As an alternative or addition to the exemplary embodiments so far described, a network system which is particularly advantageous with regard to safety aspects provides that pilot radiation can be coupled into the light path in each of the laser devices.
Pilot radiation of this type on the one hand allows the light path to be checked and on the other hand allows a check to be made on how the laser radiation is emerging from the laser processing head.
Pilot radiation of this type is preferably of such a low power that the pilot radiation itself does not constitute any safety or health risk.
For example, it would be conceivable to use the pilot radiation at a wavelength which is not visible. In this case, the path of the pilot radiation would have to be made visible, for example by an operator, by auxiliary means, such as for example fluorescent objects or vapor with fluorescent substances.
However, it is particularly advantageous if the pilot radiation is in the range of wavelengths visible to the human eye.
Consequently, an operator has the possibility on the one hand of checking with the naked eye whether a continuous light path from one of the laser devices to the laser processing head exists and on the other hand of detecting how the laser processing head will also later guide and align the laser radiation of the laser device.
However, apart from the simple detection of the pilot radiation with the human eye, the pilot radiation can also be used for transmitting information.
For example, the pilot radiation of different laser devices may have a different wavelength, which makes it possible to identify the origin of the pilot radiation just with the naked eye, from the different color.
Since, however, pilot radiation is only available at low cost with what are known as pilot lasers, which operate in a range of visible wavelengths, it is preferably provided that the pilot radiation is information-modulated.
The information modulation of the pilot radiation can in this case be performed in a wide variety of ways.
It is particularly favorable if the pilot radiation coupled into the light path in each laser device is modulated device-specifically, that is to say has a modulation specifically for each device, so that the laser device can be detected on the basis of this modulation of the pilot radiation.
It is even more advantageous if the pilot radiation is modulated output-specifically, that is to say it can be detected from the pilot radiation from which output of which laser device this pilot radiation originates, so that an operator can directly identify the output of the laser device on the basis of detecting the pilot radiation.
With regard to the modulation of the pilot radiation, there continues therefore to be a wide variety of conceivable possibilities. For example, it is conceivable to modulate the pilot radiation with regard to its wavelength, the wavelength modulation either being such that it is not directly visible to the eye or such that it is visible to the naked eye as color modulation.
However, it is even more simple than a frequency modulation or wavelength modulation if the pilot radiation is intensity-modulated.
Such a modulation of the intensity of the pilot radiation can likewise be performed either by the modulation being carried out with the naked eye, for example as rapid blinking or slow blinking, or else for example as flashing, that is to say brief intensity maxima alternating with long intensity minima.
However, it is also conceivable to carry out the intensity modulation in such a way that it cannot be detected with the naked eye.
No details have previously been specified regarding the coupling of the pilot radiation into the light path. It is particularly favorable if the pilot radiation in the laser device is coupled into the light path ahead of the output, since it is consequently ensured that the pilot radiation runs through the entire light path and consequently that defects in the light path or poor connections in the light path can be detected on the basis of the pilot radiation.
A particularly favorable solution provides that the pilot radiation can be coupled into the light path at the shutter switch, so that the entire light path from the shutter switch can be traced directly on the basis of the pilot radiation.
It is particularly favorable if the shutter switch is constructed in such a way that the pilot radiation can be coupled into the light path without additional optical elements.
Furthermore, as the last component switching the laser radiation, for example with a deflecting element, the shutter switch offers the possibility of coupling in the pilot radiation in a simple way.
In principle, it would be conceivable in the exemplary embodiments described so far to guide the pilot radiation on its own or to guide the pilot radiation together with the laser radiation, so that it would always be possible to detect from the pilot radiation the path or impingement of the laser radiation on the workpiece or other locations of the workstation.
However, it is particularly favorable if the coupling-in of the pilot radiation can be switched with the shutter switch and the pilot radiation is coupled into the light path when the shutter switch is in the open position, that is to say is interrupting the light path.
This solution has the great advantage that an operator can consequently detect with the naked eye, just from the existence of the pilot radiation, that no laser radiation can come from the laser radiation source via this light path at this moment, since the presence of the pilot radiation is a clear indication that the shutter switch is open and is consequently not capable of coupling laser radiation from the laser radiation source into the light path.
It is particularly suitable in this case if the shutter switch in the closed position interrupts the coupling-in of the pilot radiation. For example, in this case it is conceivable for the shutter switch to deflect the pilot radiation.
Consequently, the absence of the pilot radiation is an indication to the operator that laser radiation may arrive at the laser processing head.
With regard to the possibilities for sensing the pilot radiation, no additional possibilities beyond the simple detection of the pilot radiation by an operator have been presented in connection with the explanation so far of the individual exemplary embodiments.
Consequently, an advantageous solution provides that the pilot radiation can be detected by a detector of an information acquisition device and that the information contained in the pilot radiation can be ascertained by the information acquisition device from the modulation of the pilot radiation.
It is to be regarded as the advantage of this solution that the pilot radiation can consequently be modulated in such a way that the modulation cannot be detected with the naked eye, such rapid modulation having the advantage that considerable amounts of information can be transmitted.
An information acquisition device of this type may in principle be formed as a device which is available to the operator and is carried around by the operator and held in the light path of the pilot radiation as and when required, so that the detector can detect said pilot radiation and ascertain the information.
However, it is also conceivable for the information acquisition device to be fixed in the workstation or else for example be associated with the laser processing head.
A particularly advantageous solution envisages that the information acquisition device is able to identify the laser device, so that for example an operator can use the information acquisition device to identify in a simple way the laser device from which the pilot radiation is coming.
It is even more advantageous if the used output of the laser device, and consequently also the light path respectively being used, can also be identified with the information acquisition device.
This can be achieved in a particularly simple way by the information acquisition device being able to display the information ascertained, this is to say for example the information ascertained concerning the identity of the laser device.
With regard to the way in which the pilot radiation is sensed, a wide variety of possibilities are conceivable. For example, it is conceivable for the detector of the information acquisition device to sense scattered light of the light path, so that the detector does not have to be placed directly in the light path.
For example, detectors of this type can be provided not only the light path in the optical connection elements, but also in the mating connection part or else in the laser processing head, in all of which scattered light of the pilot radiation is produced during the transition from one optical element to the other optical element, so that the information transmitted by modulation of the pilot radiation can already be ascertained on the basis of the scattered light, that is to say it is possible for example for the laser device and possibly also the light path to be identified.
Another solution envisages that the laser processing head can be positioned in relation to the detector in such a way that the detector senses the pilot radiation directly.
This solution has the advantage that it allows the pilot radiation to operate with low power, which would for example produce an inadequate intensity for detection in the scattered light but is adequate for ascertainment of the information if the pilot radiation from the laser processing head acts directly on the detector.
Moreover, this solution also has the advantage that gradual defects, such as for example intensity-reducing effects, can be detected by determining the absolute intensity of the pilot radiation.
Such a use of pilot radiation, explained in the above exemplary embodiments, in a network system according to the invention can be employed particularly suitably if the light path monitoring system senses the presence of pilot radiation coupled-in the laser device at the laser processing head.
Such a form of the light path monitoring system consequently allows the light path to be monitored in a simple way to establish whether all the connection elements and mating connection parts are in connection and also whether there is no damage to the optical elements, such as for example the light guides and/or coupling optics.
It is also particularly favorable if the light path monitoring system monitors the presence of pilot radiation coupled-in the laser device at the optical connection, that is to say at the optical connection element or at the mating optical connection part, since these are primarily sources of error when they are to be brought into connection with one another by the operator.
Further features of the invention are the subject of the following description and the graphic representation of a of an exemplary embodiment of a network system according to the invention.